1. Field of the Invention
The present invention relates to a method and an apparatus for carrying out image processing on image data obtained by a digital camera. The present invention also relates to a program that causes a computer to execute the image processing method.
2. Description of the Related Art
In a digital electronic still camera (hereinafter referred to as a digital camera), an image obtained by photography can be recorded as digital image data in a recording medium such as an internal memory or an IC card, and can be reproduced by a printer or a monitor based on the digital image data. In the case where an image obtained by a digital camera is printed, the image is expected to have as high a quality as a print generated from a negative film.
When a print is generated in the above manner, a quality of the print can be improved by carrying out thereon image processing such as density conversion processing, white balance processing, gradation conversion processing, saturation enhancement processing, and sharpness processing. Therefore, a method for obtaining a high-quality print has been proposed (U.S. Pat. No. 6,011,547). In this method, photography information such as information on an ON or OFF state of flash and the type of lighting is attached as tag information to image data obtained by a digital camera, and more appropriate image processing can be carried out on the image data with reference to the photography information attached to the image data.
The tag information also includes information that is useful for image processing, in addition to the information on the ON or OFF state of flash and the type of lighting. For example, the tag information includes information on a distance to a subject, brightness of the subject, the exposure, a photometric quantity at the time of photography, and presence or absence of backlight. Therefore, various methods have been proposed for carrying out image processing on image data with use of the photography information (U.S. Pat. Nos. 6,133,983, 5,739,924, 5,016,039, 5,596,387 and 5,710,948 and Japanese Unexamined Patent Publication Nos. 8(1996)-307767 and 11(1999)-88576, for example).
In the image processing methods described above, appropriate image processing is carried out on the image data by using the photography information. However, if a subject such as people or scenery included in an image represented by image data varies, an appropriate condition for the image processing cannot be found with accuracy if the photography information is used alone.
Meanwhile, a photography mode (such as portrait mode, scenery/distant view mode, macro/close-up mode, night view/fireworks mode, marine photograph mode, and user exposure correction mode) may be obtained as a portion of the photography information so that the image processing condition can be found based on the photography mode. However, a user may photograph scenery in the portrait mode, for example. If the photography mode is set erroneously in a digital camera, the image processing condition cannot be found appropriately.